Cleaning wipe comprising antioxidizing agent

ABSTRACT

A cleaning wipe comprising a single layer needle punched fabric wherein the fabric is impregnated with a cleaning composition.

FIELD OF INVENTION

The present invention relates to a cleaning wipe which is single layerfabric substrate has been impregnated with a liquid cleaningcomposition.

BACKGROUND OF THE INVENTION

The patent literature describes numerous wipes for both body cleaningand cleaning of hard surfaces but none describe wipes for cleaningdishware flatware, pots and pans U.S. Pat. Nos. 5,980,931, 6,063,397 and6,074,655 teach a substantially dry disposable personal cleansingproduct useful for both cleansing and conditioning the skin and hair.U.S. Pat. No. 6,060,149 teaches a disposable wiping article having asubstrate comprising multiple layers.

U.S. Pat. Nos. 5,756,612; 5,763,332; 5,908,707; 5,914,177; 5,980,922 and6,168,852 teach cleaning compositions which are inverse emulsions.

U.S. Pat. Nos. 6,183,315 and 6,183,763 teach cleaning compositionscontaining a proton donating agent and having an acidic pH. U.S. Pat.Nos. 5,863,663; 5,952,043; 6,063,746 and 6,121,165 teaches cleaningcompositions which are oil in water emulsions.

SUMMARY OF THE INVENTION

A single use cleaning wipe for dishwashing application comprises a waterinsoluble substrate, impregnated with a cleaning composition containingan anionic sulfonated surfactant, an alkyl polyglucoside surfactant, analkyl monoalkanol amide, an ethoxylated alkyl ether sulfate surfactant,a C₁-C₄ alkanol and water.

The liquid cleaning compositions of this invention are not an emulsionand do not contain proteins, enzymes, sodium hypochlorite, dimethicone,N-methyl-2-pyrrolidone, monoalkyl phosphate or silicone basedsulfosuccinate.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a cleaning wipe for dishware, flatware,pots and pans which comprises approximately:

(a) 20 wt. % to 95 wt. % of a water insoluble substrate; and

(b) 5 wt. % to 80 wt. % of a liquid cleaning composition beingimpregnated in said water insoluble substrate, wherein said liquidcleaning composition comprises:

(i) 20 wt. % to 30 wt. % of an alkaline earth or alkali metal salt of ananionic sulfonated surfactant;

(ii) 2 wt. % to 12 wt. % of an alkali metal salt of an ethoxylated alkylether sulfate surfactant;

(iii) 0.5 wt. % to 10 wt. % of an alkyl polyglucoside surfactant;

(iv) 0.5 wt. % to 6 wt. % of a C₁₂-C₁₄ alkyl monoalkanol amide such aslauryl monalkanol amide;

(v) 1 wt. % to 8 wt. % of a C₁-C₄ alkanol;

(vi) 0 to 5 wt. %, more preferably 0.1 wt. % to 4 wt. % of a protondonating agent;

(vii) 0 to 6 wt. %, more preferably 0.1 wt. % to 4 wt. % of apolyethylene glycol;

(viii) 0 to 6 wt. %, more preferably 0.5 wt. % to 5 wt. % of sodiumxylene sulfonate and/or sodium cumene sulfonate; and

(ix) the balance being water.

The present invention also relates to a cleaning wipe which comprisesapproximately:

(a) 20 wt. % to 95 wt. % of a water insoluble substrate;

(b) 5 wt. % to 80 wt. % of a liquid cleaning composition beingimpregnated in said water insoluble substrate, wherein said liquidcleaning composition comprises:

(i) 2 wt. % to 12 wt. % of an alkaline earth metal salt of a sulfonatesurfactant;

(ii) 2 wt. % to 12 wt. % of an alkali metal salt of a sulfonatesurfactant;

(iii) 5 wt. % to 18 wt. % of an alkali metal salt of an ethoxylatedalkyl ether sulfate surfactant;

(iv) 5 wt. % to 18 wt. % of an alkyl polyglucoside surfactant;

(v) 1 wt. % to 10 wt. % of an amine oxide surfactant;

(vi) 1 wt. % to 8 wt. % of a C₁-C₄ alkanol;

(vii) 0.5 wt. % to 6 wt. % of sodium xylene sulfonate and/or sodiumcumene sulfonate; and

(viii) the balance being water.

Suitable water-soluble non-soap, anionic surfactants used in the instantcompositions include those surface-active or detergent compounds whichcontain an organic hydrophobic group containing generally 8 to 26 carbonatoms and preferably 10 to 18 carbon atoms in their molecular structureand at least one water-solubilizing group selected from the group ofsulfonate, sulfate and carboxylate so as to form a water-solubledetergent. Usually, the hydrophobic group will include or comprise aC₈-C₂₂ alkyl, alkyl or acyl group. Such surfactants are employed in theform of water-soluble salts and the salt-forming cation usually isselected from the group consisting of sodium, potassium, ammonium,magnesium and mono-, di- or tri-C₂-C₃ alkanolammonium, with the sodium,magnesium and ammonium cations again being preferred.

Examples of suitable sulfonated anionic surfactants are the well knownhigher alkyl mononuclear aromatic sulfonates such as the higher alkylbenzene sulfonates containing from 10 to 16 carbon atoms in the higheralkyl group in a straight or branched chain, C₈-C₁₅ alkyl toluenesulfonates and C₈-C₁₅ alkyl phenol sulfonates.

A preferred sulfonate is linear alkyl benzene sulfonate having a highcontent of 3- (or higher) phenyl isomers and a correspondingly lowcontent (well below 50%) of 2- (or lower) phenyl isomers, that is,wherein the benzene ring is preferably attached in large part at the 3or higher (for example, 4, 5, 6 or 7) position of the alkyl group andthe content of the isomers in which the benzene ring is attached in the2 or 1 position is correspondingly low.

Other suitable anionic surfactants are the olefin sulfonates, includinglong-chain alkene sulfonates, long-chain hydroxyalkane sulfonates ormixtures of alkene sulfonates and hydroxyalkane sulfonates. These olefinsulfonate detergents may be prepared in a known manner by the reactionof sulfur trioxide (SO₃) with long-chain olefins containing 8 to 25,preferably 12 to 21 carbon atoms and having the formula RCH═CHR₁ where Ris a higher alkyl group of 6 to 23 carbons and R₁ is an alkyl group of 1to 17 carbons or hydrogen to form a mixture of sultones and alkenesulfonic acids which is then treated to convert the sultones tosulfonates. Preferred olefin sulfonates contain from 14 to 16 carbonatoms in the R alkyl group and are obtained by sulfonating an α-olefin.

Other examples of suitable anionic sulfonate surfactants are theparaffin sulfonates containing 10 to 20, preferably 13 to 17, carbonatoms. Primary paraffin sulfonates are made by reacting long-chain alphaolefins and bisulfites and paraffin sulfonates having the sulfonategroup distributed along the paraffin chain are shown in U.S. Pat. Nos.2,503,280; 2,507,088; 3,260,744; 3,372,188; and German Patent 735,096.

Examples of satisfactory anionic sulfate surfactants are the C₈-C₁₈alkyl sulfate salts the ethoxylated C₈-C₁₈ alkyl ether sulfate saltshaving the formula R(OC₂H₄)_(n)OSO₃M wherein n is 1 to 12, preferably 1to 5, and M is a metal cation selected from the group consisting ofsodium, potassium, ammonium, magnesium and mono-, di- and triethanolammonium ions. The alkyl sulfates may be obtained by sulfating thealcohols obtained by reducing glycerides of coconut oil or tallow ormixtures thereof and neutralizing the resultant product.

On the other hand, the ethoxylated alkyl ether sulfates are obtained bysulfating the condensation product of ethylene oxide with a C₈-C₁₈alkanol and neutralizing the resultant product. The alkyl sulfates maybe obtained by sulfating the alcohols obtained by reducing glycerides ofcoconut oil or tallow or mixtures thereof and neutralizing the resultantproduct. The ethoxylated alkyl ether sulfates differ from one another inthe number of moles of ethylene oxide reacted with one mole of alkanol.Preferred alkyl sulfates and preferred ethoxylated alkyl ether sulfatescontain 10 to 16 carbon atoms in the alkyl group.

The ethoxylated C₈-C₁₂ alkylphenyl ether sulfates containing from 2 to 6moles of ethylene oxide in the molecule also are suitable for use in theinventive compositions. These surfactants can be prepared by reacting analkyl phenol with 2 to 6 moles of ethylene oxide and sulfating andneutralizing the resultant ethoxylated alkylphenol.

Other suitable anionic surfactants are the C₉-C₁₅ alkyl etherpolyethenoxyl carboxylates having the structural formulaR(OC₂H₄)_(n)OXCOOH wherein n is a number from 4 to 12, preferably 5 to10 and X is selected from the group consisting of

wherein R₁ is a C₁-C₃ alkylene group. Preferred compounds include C₉-C₁₁alkyl ether polyethenoxy (7-9) C(O)CH₂CH₂COOH, C₁₃-C₁₅ alkyl etherpolyethenoxy (7-9)

and C₁₀-C₁₂ alkyl ether polyethenoxy (5-7) CH2COOH. These compounds maybe prepared by condensing ethylene oxide with appropriate alkanol andreacting this reaction product with chloracetic acid to make the ethercarboxylic acids as shown in U.S. Pat. No. 3,741,911 or with succinicanhydride or phthalic anhydride. Obviously, these anionic surfactantswill be present either in acid form or salt form depending upon the pHof the final composition, with salt forming cation being the same as forthe other anionic surfactants.

The amine oxide semi-polar nonionic surfactants comprise compounds andmixtures of compounds having the formula

wherein R₁ is an alkyl, 2-hydroxyalkyl, 3-hydroxyalkyl, or3-alkoxy-2-hydroxypropyl radical in which the alkyl and alkoxy,respectively, contain from 8 to 18 carbon atoms, R₂ and R₃ are eachmethyl, ethyl, propyl, isopropyl, 2-hydroxyethyl, 2-hydroxypropyl, or3-hydroxypropyl, and n is from 0 to 10. Particularly preferred are amineoxides of the formula:

wherein R₁ is a C₁₂₋₁₆ alkyl and R₂ and R₃ are methyl or ethyl. Theabove ethylene oxide condensates, amides, and amine oxides are morefully described in U.S. Pat. No. 4,316,824 which is hereby incorporatedherein by reference.

The alkyl polysaccharides surfactants, which are used in conjunctionwith the anionic surfactants have a hydrophobic group containing fromabout 8 to about 20 carbon atoms, preferably from about 10 to about 16carbon atoms, most preferably from about 12 to about 14 carbon atoms,and polysaccharide hydrophilic group containing from about 1.5 to about10, preferably from about 1.5 to about 4, most preferably from about 1.6to about 2.7 saccharide units (e.g., galactoside, glucoside, fructoside,glucosyl, fructosyl; and/or galactosyl units). Mixtures of saccharidemoieties may be used in the alkyl polysaccharide surfactants. The numberx indicates the number of saccharide units in a particular alkylpolysaccharide surfactant. For a particular alkyl polysaccharidemolecule x can only assume integral values. In any physical sample ofalkyl polysaccharide surfactants there will be in general moleculeshaving different x values. The physical sample can be characterized bythe average value of x and this average value can assume non-integralvalues. In this specification the values of x are to be understood to beaverage values. The hydrophobic group (R) can be attached at the 2-, 3-,or 4- positions rather than at the 1-position, (thus giving e.g. aglucosyl or galactosyl as opposed to a glucoside or galactoside).However, attachment through the 1- position, i.e., glucosides,galactoside, fructosides, etc., is preferred. In the preferred productthe additional saccharide units are predominately attached to theprevious saccharide unit's 2-position. Attachment through the 3-, 4-,and 6- positions can also occur. Optionally and less desirably there canbe a polyalkoxide chain joining the hydrophobic moiety (R) and thepolysaccharide chain. The preferred alkoxide moiety is ethoxide.

Typical hydrophobic groups include alkyl groups, either saturated orunsaturated, branched or unbranched containing from about 8 to about 20,preferably from about 10 to about 18 carbon atoms. Preferably, the alkylgroup is a straight chain saturated alkyl group. The alkyl group cancontain up to 3 hydroxy groups and/or the polyalkoxide chain can containup to about 30, preferably less than about 10, alkoxide moieties.

Suitable alkyl polysaccharides are decyl, dodecyl, tetradecyl,pentadecyl, hexadecyl, and octadecyl, di-, tri-, tetra-, penta-, andhexaglucosides, galactosides, lactosides, fructosides, fructosyls,lactosyls, glucosyls and/or galactosyls and mixtures thereof.

The alkyl monosaccharides are relatively less soluble in water than thehigher alkyl polysaccharides. When used in admixture with alkylpolysaccharides, the alkyl monosaccharides are solubilized to someextent. The use of alkyl monosaccharides in admixture with alkylpolysaccharides is a preferred mode of carrying out the invention.Suitable mixtures include coconut alkyl, di-, tri-, tetra-, andpentaglucosides and tallow alkyl tetra-, penta-, and hexaglucosides.

The preferred alkyl polysaccharides are alkyl polyglucosides having theformula

R₂O(C_(n)H_(2n)O)r(Z)_(x)

wherein Z is derived from glucose, R is a hydrophobic group selectedfrom the group consisting of alkyl, alkylphenyl, hydroxyalkylphenyl, andmixtures thereof in which said alkyl groups contain from about 10 toabout 18, preferably from about 12 to about 14 carbon atoms; n is 2 or 3preferably 2, r is from 0 to 10, preferable 0; and x is from 1.5 to 8,preferably from 1.5 to 4, most preferably from 1.6 to 2.7. To preparethese compounds a long chain alcohol (R₂OH) can be reacted with glucose,in the presence of an acid catalyst to form the desired glucoside.Alternatively the alkyl polyglucosides can be prepared by a two stepprocedure in which a short chain alcohol (R₁OH) can be reacted withglucose, in the presence of an acid catalyst to form the desiredglucoside. Alternatively the alkyl polyglucosides can be prepared by atwo step procedure in which a short chain alcohol (C₁₋₆) is reacted withglucose or a polyglucoside (x=2 to 4) to yield a short chain alkylglucoside (x=1 to 4) which can in turn be reacted with a longer chainalcohol (R₂OH) to displace the short chain alcohol and obtain thedesired alkyl polyglucoside. If this two step procedure is used, theshort chain alkylglucosde content of the final alkyl polyglucosidematerial should be less than 50%, preferably less than 10%, morepreferably less than about 5%, most preferably 0% of the alkylpolyglucoside.

The amount of unreacted alcohol (the free fatty alcohol content) in thedesired alkyl polysaccharide surfactant is preferably less than about2%, more preferably less than about 0.5% by weight of the total of thealkyl polysaccharide. For some uses it is desirable to have the alkylmonosaccharide content less than about 10%.

The used herein, “alkyl polysaccharide surfactant” is intended torepresent both the preferred glucose and galactose derived surfactantsand the less preferred alkyl polysaccharide surfactants. Throughout thisspecification, “alkyl polyglucoside” is used to include alkylpolyglycosides because the stereochemistry of the saccharide moiety ischanged during the preparation reaction.

An especially preferred APG glycoside surfactant is APG 625 glycosidemanufactured by the Henkel Corporation of Ambler, Pa. APG25 is anonionic alkyl polyglycoside characterized by the formula:

C_(n)H_(2n+1)O(C₆H₁₀O₅)_(x)H

wherein n=10 (2%); n=122 (65%); n=14 (21-28%); n=16 (4-8%) and n=18(0.5%) and x (degree of polymerization)=1.6. APG 625 has: a pH of 6 to10 (10% of APG 625 in distilled water); a specific gravity at 25° C. of1.1 g/ml; a density at 25° C. of 9.1 lbs/gallon; a calculated HLB of12.1 and a Brookfield viscosity at 35C, 21 spindle, 5-10 RPM of 3,000 to7,000 cps.

The anionic and alkyl polyglucoside surfactants discussed above aresolubilized in an aqueous medium comprising water and optionally,solubilizing ingredients such as C₁-C₄ alkanols and dihydroxy alkanolssuch as ethanol isopropanol and propylene glycol. Suitable water solublehydrotropic salts include sodium, potassium, ammonium and mono-, di- andtriethanolammonium salts of xylene and cumene sulfonates. While theaqueous medium is primarily water, preferably said solubilizing agentsare included in order to control the viscosity of the liquid compositionand to control low temperature cloud clear properties. Usually, it isdesirable to maintain clarity to a temperature in the range of 5° C. to10° C. Therefore, the proportion of solubilizer generally will be fromabout 1% to 15%, preferably 2% to 12%, most preferably 3% to 8%, byweight of the detergent composition with the proportion of ethanol, whenpresent, being 5% of weight or less in order to provide a compositionhaving a flash point above about 46° C. Preferably the solubilizingingredient will be a mixture of ethanol and either sodium xylenesulfonate or sodium cumene sulfonate or a mixture of said sulfonates orethanol and urea. Inorganic salts such as sodium sulfate, magnesiumsulfate, sodium chloride and sodium citrate can be added atconcentrations of 0.5 to 4.0 wt. % to modify the cloud point of thenonionic surfactant and thereby control the haze of the resultantsolution. Various other ingredients such as urea at a concentration ofabout 0.5 to 4.0 wt. % or urea at the same concentration in combinationwith ethanol at a concentration of about 0.5 to 4.0 wt. % can be used assolubilizing agents. Other ingredients which have been added to thecompositions at concnetrations of about 0.1 to 4.0 wt. percent areperfumes, sodium bisulfite, ETDA, isoethanoeic and proteins such aslexine protein.

Polyethylene glycol maybe is used in the instant composition has amolecular weight of 200 to 1,000 wherein the polyethylene glycol has thestructure

HO(CH₂CH₂O)_(n)H

wherein n is 4 to 52. The concentration of the polyethylene glycol inthe instant composition is 0 to 7 wt. %, more preferably 0.1 wt. % to 5wt. %.

The proton donating agent is selected from the group consisting ofinorganic acids such as sulfuric acid and hydrochloric acid and hydroxycontaining organic acid, preferably a hydroxy aliphatic acid, which areselected from the group consisting of lactic acid or citric acid,orthohydroxy benzoic acid or citric acid or glycolic and mixturesthereof.

The water is present in the composition at a concentration of about 5wt. % to 70 wt. %.

The cleaning composition of this invention may, if desired, also containother components either to provide additional effect or to make theproduct more attractive to the consumer. The following are mentioned byway of example: Antibacterial agents such as2,4,4′-trichloro-2′hydroxydiphenyl ether colors or dyes in amounts up to0.5% by weight; preservatives or antioxidizing agents, such as formalin,5-bromo-5-nitro-dioxan-1,3; 5-chloro-2-methyl4-isothaliazolin-3-one,2,6-di-tert.butyl-p-cresol, etc., in amounts up to 2% by weight; and pHadjusting agents, such as sulfuric acid or sodium hydroxide, as needed.

The product of the present invention comprises a water insoluablesubstrate with one or more layers. Each layer may have differenttextures and abrasiveness. Differing textures can result from the use ofdifferent combinations of materials or from the use of differentmanufacturing processes or a combination thereof. A dual texturesubstrate can be made to provide the advantage of a more abrasive sidefor cleaning difficult to remove soils. A softer side can be used forfine dishware and flatware. The substrate should not dissolve or breakapart in water. It is the vehicle for delivering the cleaningcomposition to dishware, flatware, pots and pans. Use of the substrateenhances lathering, cleaning and grease removal.

A wide variety of materials can be used as the substrate. It should havesufficient wet strength, abrasivity, loft and porosity. Examplesinclude, non woven substrates, wovens substrates, hydroentangledsubstrates and sponges.

Examples of suitable non woven water insoluable substrates include, 100%cellulose Wadding Grade 1804 from Little Rapids Corporation, 100%polypropylene needlepunch material NB 701-2.8—W/R from AmericanNon-wovens Corporation, a blend of cellulosic and syntheticfibres-Hydraspun 8579 from Ahistrom Fibre Composites, and &0%Viscose/30% PES Code 9881 from PGI Nonwovens Polymer Corp.

The product of the present invention comprising mutliple layers may beultrasonically bonded after applying the coating of one or more of thelayers. Alternatively layers may be bonded together by needlepunch,thermal bonding, chemical bonding, or sonic bonding prior to applyingthe coating.

The following examples illustrate liquid cleaning compositions of thedescribed invention. Unless otherwise specified, all percentages are byweight. The exemplified compositions are illustrative only and do notlimit the scope of the invention. Unless otherwise specified, theproportions in the examples and elsewhere in the specification are byweight.

EXAMPLE 1

The following compositions (in wt. %) were prepared by simple batchmixing at room temperature. The cleaning wipe was made by the previouslydescribed impregnation process.

Part I A Ammonium ethoxylated alkyl ether sulfate 15.34 Magnesium linearalkyl benzene sulfonate 26.6 Lauryl polyglucoside 3.3 Lauramidemyristamide monoethanol amide 3.5 Sodium xylene sulfonate 4.0 Ethanol1.8 Sodium bisulfite 0.2 HEDTA 0.67 Preservative 0.47 Water Bal. Part 1Formula A 1 3 NB-701-2.8/WR fabric 1 Wadding Grade 1804 1 SRF #8265C 1SRF 1262 1

While particular embodiments of the invention and the best modecontemplated by the inventors for carrying out the invention have beenshown, it will be understood, of course, that the invention is notlimited thereto since modifications may be made by those skilled in theart, particularly in light of the foregoing teachings. It is, therefore,contemplated by the appended claims to cover any such modifications asincorporate those features which constitute the essential features ofthese improvements within the true spirit and scope of the invention.

What is claimed:
 1. A hard surface cleaning wipe which comprisesapproximately: (a) 20 wt. % to 95 wt. % of a water insoluble substrate;and (b) 5 wt. % to 80 wt. % of a liquid cleaning composition beingimpregnated in a nonwoven fabric, wherein said liquid cleaningcomposition comprises: (i) 20 wt. % to 30 wt. % of an anionic sulfonatesurfactant; (ii) 2 wt. % to 12 wt. % of an anionic sulfate surfactant;(iii) 0.5% to 10% of an alkyl polyglucoside surfactant; (iv) 0.5 wt. %to 6 wt. % of a C₁₂-C₁₄ alkyl monoalkanol amide such as laurylmonalkanol amide; (v) 1 wt. % to 8 wt. % of a C₁-C₄ alkanol; (vi) about2% by weight of a preservative selected from the group consisting of5-nitrodioxan-1,3 and 5-chioro-2-methyl-4-isothaliazoin-3-one; (vii) 0.1to 4 wt. % of a polyethylene glycol; and (viii) the balance being water.2. The wipe according to claim 1, further including an alkali metal saltof cumene sulfonate or xylene sulfonate.
 3. The wipe according to claim1, wherein said sulfonate surfactant is a linear C₁₀-C₁₆ alkyl benzenesulfonate.
 4. The wipe according to claim 1, wherein said sulfatesurfactant is an ethoxylated C₈-C₁₈ alkyl ether sulfate.
 5. The wipeaccording to claim 1, further including about 0.01 to about 1.5 wt. % ofa perfume.
 6. The wipe according to claim 1, further including a protondonating agent.
 7. The wipe according to claim 1, wherein said waterinsoluble substrate comprises one or more materials selected fromnonwoven substrates, woven substrates, hydroentangeld substrates andsponges.
 8. A method of manufacturing a product according to claim 1,wherein the cleaning composition is added or impregnated into the waterinsoluble substrate by spraying, dipping, extrusion coating or slotcoating.
 9. The wipe according to claim 1, wherein said liquid cleaningcomposition includes sodium xylene sulfonate and/or sodium cumenesulfonate.
 10. A cleaning wipe which comprises approximately: (a) 20 wt.% to 95 wt. % of a water insoluble substrate; (b) 5 wt. % to 80 wt. % ofa liquid cleaning composition being impregnated in said water insolublesubstrate, wherein said liquid cleaning composition comprises: (i) 2 wt.% to 12 wt. % of an alkaline earth metal salt of a sulfonate surfactant;(ii) 2 wt. % to 12 wt. % of an alkali metal salt of a sulfonatesurfactant; (iii) 5 wt. % to 18 wt. % of an alkali metal salt of anethoxylated alkyl ether sulfate surfactant; (iv) 5 wt. % to 18 wt. % ofan alkyl polyglucoside surfactant; (v) 1 wt. % to 10 wt. % of an amineoxide surfactant; (vi) 1 wt. % to 8 wt. % of a C₁-C₄ alkanol; (vii) 0.5wt. % to 6 wt. % of sodium xylene sulfonate and/or sodium cumenesulfonate; about 2% by weight of a preservative selected from the groupconsisting of 5-bromo-5-nitro-dioxan-1,3 and 5-chloro-2-methyl4-isothaliazolin-3-one; (vii) 0.1 to 4 wt. % of a polyethylene glycol;and (viii) the balance being water.